[PATCH v3 27/35] x86/bugs: Add attack vector controls for gds

David Kaplan
2025-01-08T20:25:55Z

Use attack vector controls to determine if gds mitigation is required.

Signed-off-by: David Kaplan <david.kaplan@amd.com>
---
arch/x86/kernel/cpu/bugs.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index c6b395608c3f..9c9299b988d1 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1058,8 +1058,14 @@ static void __init gds_select_mitigation(void)
gds_mitigation = GDS_MITIGATION_OFF;
/* Will verify below that mitigation _can_ be disabled */

- if (gds_mitigation == GDS_MITIGATION_AUTO)
- gds_mitigation = GDS_MITIGATION_FULL;
+ if (gds_mitigation == GDS_MITIGATION_AUTO) {
+ if (should_mitigate_vuln(X86_BUG_GDS))
+ gds_mitigation = GDS_MITIGATION_FULL;
+ else {
+ gds_mitigation = GDS_MITIGATION_OFF;
+ return;
+ }
+ }

/* No microcode */
if (!(x86_arch_cap_msr & ARCH_CAP_GDS_CTRL)) {
--
2.34.1